Valve-gear for steam-engines



UNITED STATES PAT'EN T OFFICE.

PETER LOUIS, OF NE\V YORK, N. Y., ASSIGNOR TO HIMSELF, AND HARAM VAUDEL,OF CASTLETON, I\'E\V YORK.

VALVE-GEAR FOR STEAM-ENGINES.

Specification of Letters Patent No. 29,844, dated August 28, 1860.

To all whom it may concern:

Be it known that I, PETER LoUrs, of the city, county, and State of NewYork, have invented a new and Improved Valve-Gear for Steam-Engines; andI do hereby declare that the following is a full, clear, and exactdescription of the same, reference being had to the accompanyingdrawing, forming part of this specification, in which- Figure l is aside view illustrating` the application of my invention to a horizontal.engine and showing the steam chest and valve in section. Fig. 2 is aplan of the same exhibiting the variable cut-ofi1 apparatus in section.

Similar letters of reference indicate corresponding parts in bothfigures.

My invention consists principally in the .combination with a yokeconnected with the valve or valves employed for the induc- Vjtion andcutting off the steam and with a rocker deriving motion from the mainshaft of the engine and operating within and upon lthe said yoke to openthe valve or valves .at the proper time for the induction of steam, oftwo adjustable tappet pieces fitted to the yoke as hereinafter describedfor the purpose of being operated upon by an arm of the rocker to effectthe closing of the valve or valves and consequent cutting off of thesteam at such point-s in the stroke of the piston as may be desirable.

To enable others skilled in the art to make and use my invention I willproceed to describe its construction -and operation.

A, represents the steam chest of the engine.

0;, b, are the steam with opposite ends of is the exhaust port.

B, is a slide valve working over the three ports. This valve should beof the double la kind in order that it may, after cutting offp the steamfrom one steam port a, or b, continue to keep the other one open to theexhaust port c.

C, is the yoke having rigidly attached to it two rods (l, and e, ofwhich the latter is connected by a pin joint f, with the stem g, of thevalve and the former is arranged to work in a guide D, under a fixed pinz', against which it is held by a spring j, in the lower part of theguide except at the times hereinafter explained.

E, is a rock shaft working in suitable ports communicating the cylinder,and c,

fixed bearings 7c, 7c, and passing through the yoke C. This rockshafthas securely attached to it an arm K, which is connected by a rod L,with an eccentric M, on the main shaft N, of the engine and it has alsosecured firmly upon it a three armed rocker F, G, H, which works withinthe yoke. Two arms F, Gr, of this rocker operate upon two inwardprojections Z, m, in the lower part of the yoke, to give the valve thenecessary movements for the induction of steam to the two ports a, andb, alternately, and the third arm H, operates upon the two adjustabletappet pieces n, n', which project through slots provided for them inthe upper part of the yoke. These tappet pieces are attached rigidly toor formed upon the ends of a bar I, which is attached to the yoke bymeans of a screw J, so applied that by turning the said screw the saidbar may be lowered or raised and the tappets caused to project farther'or not so far into the yoke. The said tappets have the faces which areacted upon by the arm I-I, of the rocker of rounded form, and the end ofthe said arm as well as the ends of the other arms of the rocker arerounded.

The operation of the valve gear is as follows: The revolution of theeccentric produces an oscillating movement of the rock shaft E, withinthe yoke C, and causes the arms F, G, to act upon the projections Z, m,to move the yoke to make the valve open the ports a, Z), to the stealnat the proper time and the arm H, to act upon the tappet pieces n, 11X,to move the yoke to make the valve close the ports to the steam at theproper time the closing movement and cutting off of the steam takingplace later or earlier in the stroke according as the tappet piecesproject farther or not so far into the yoke. To illustrate this movementmore fully I will first suppose the crank rotating in the directionindicated in Fig. l, and to have arrived nearly on the center. Therocker operated by the eccentric (which is set with a lead) is moving inthe direction of the arrow shown within the yoke in Fig. l, and the armG, is acting upon the projection m, of the yoke and so moving the valvein the direction of the arrow marked on its stem in Fig. l, off the porta, which is being opened to the steam while Z), is being opened to theexhaust. By the time the port a, is fully opened to the steam the arm G,will pass over the angular edge of the projection m, and cease to actupon the valve only depressing the yoke slightly as it passes over thesaid angle. rlhe valve then remains with the port a, open to the steam,and open to the exhaust till the arm H, by lthe continued movement ofthe rocker in the same direction comes into operation on the tappetpiece n, and moves the yoke far enough in the opposite direction to thatin which it had been previously moved by the arm G, to bring the valveover the port a, and so to cut off the steam but not far enough to openb, to the steam or even to close it to the exhaust. As the crankapproaches the opposite center to that near which it is shown in Fig. l,the direction of the movement of the rocker having changed,

the arm F, comes into operation on the pro.- jection Z, of the yoke tomove it still farther in the direction in which it had been moved by theaction of the arm H, on the tappet piece n., and the said arm, by thisaction on the yoke, opens the port b, to the steam and a, to the exhaustjust as the crank passes the center. The arm F, after having opened theports as above specified, passes over the projection Z, and the yoke andvalve remain stationary till the arm H, while the rocker still moves inthe same direction, comes into operation on the tappet piece n', andmoves the yoke and valve back in the direction first described andindicated by the arrow shown upon the stem in Fig. l, far enough toclose the port Z), and so cut off the steam but not far enough to opena, to the steam or to close it to the exhaust. As the crank againapproaches the center near which it is represented in Fig. l, thedirection of movement of the rocker having again changed the arm Gr,comes into operation again as at first described and in this way theoperation proceeds.

The arms F, and G, after having produced their movements of the valvepass over the angles of the projections Z, m; and it is to permit thisthat the spring j, is applied under the rod cZ, of the yoke, said springlifting the yoke again after it has been depressed by the arms passingover the projections in either direction.

The tappet bar I, carrying the tappet pieces n, n', may if it be desiredto employ a governor in connection with the cut 0E to regulate theengine, be connected with the governor in such a way as to be raised upto cause the tappet pieces to project not so far into the yoke by anytendency to increased speed and vice versa. It will be understood thatwhen the tappets are nearer to the center of the yoke-their adjustmentnot being radial to the center of the yokethe arm H, will have to movefarther before striking them, and vice versa.

It will be understood by engineers that by a suitable system ofconnections between the yoke and the valves this valve gear may beemployed in connection with other kinds of valves as well as inconnection with the slide valve.

lVliat I claim as my invention, and desire to secure by Letters Patent,is

1. The arrangement of the two connected adjustable tappet pieces I, I,a, n, in connection with the valve yoke G, and rocker' F, G, H,substantially as and for the purpose herein described.

2.111 combination with the above described arrangement of tappet piecesthe spring j, applied in connection with the yoke and the rockersubstantially as and for the purpose specified.

PETER Lonrs. Y

Witnesses:

W. TUsoI-r, J. W. CoouBY.

